Questions: Making and Repairing Planetoid Ships

[DivineWrath]

So High Guard 2nd edition says that a planetoid and buffered planetoid is basically a hollowed out asteroid used as the exterior of a ship.

That sounds good and all until you consider how exactly you might repair such a ship. I'm thinking of maybe using some sort of concrete paste. Likewise, what if you don't like the selection of asteroids? Can you make your own asteroid?

While I'm thinking of it, maybe you can use the waste products from an asteroid munching (mineral refinery) ship or station.

The reason I'm asking is because it is by far cheaper to build a planetoid hull than a normal hull (50,000 per ton vs. 4,000 per ton). I'm trying to find information if this is any way feasible.

 

[Condottiere]

I'd guess quick drying nickel iron, though cement or plastic may work as a temporary fix.

The formula is figuring out the size you need, then increasing that volume by a quarter, and trimming off any excess tonnage, though that's never mentioned.

It's implied you can find any size you need.

The question is if it's really hollowed out, or if caves are bored out, and grav plating added.

 

[phavoc]

I would think repairing one would be akin to putting up concrete, though it would be the type that could expand and solidify in space. In some ways, if you think about it, the 'space concrete' might be stronger than the rocky material you had to start with, owing to it's properties. A nickel-iron asteroid is still going to have a significant silicon/rock composition, as a solid nickel-iron asteroid would be a starship hull.

I don't think making your own asteroid would be allowed. It's not the same, and thus you are essentially building a starship hull.

 

[Reynard]

"The question is if it's really hollowed out, or if caves are bored out, and grav plating added.

Deck plans seem to favor tunnels and hollowed out rooms.

 

[Tom Kalbfus]

What really constitutes damage to an asteroid ship? Chipping off pieces of rock doesn't. The asteroid ship has a function part, the part which makes it a spaceship and a non-function part which is just part of the asteroid it was made out of. Chipping off pieces of that asteroid doesn't necessarily constitute damage to the ship. The rock is just the ship's hull, and an asteroid ship's hull is made out of rock, you don't repair rock! You can add mass to it, or you can increase your ship's cargo capacity with the reduction in size of your asteroid ship. What happens if you get a new crater in you asteroid ship, is that damage?

 

[Reynard]

The asteroid hull is still hull by the rules with slight modification. It protects and takes damage as a hull and is repaired as hull per 2e CRB page 150 using spare parts on board or at a shipyard. I assume part of 'spare parts' will be bags of Duracrete(TM).

 

[Condottiere]

In theory, technological level nine hulls are self-sealing; the text emphasize the word all.

Fast hardening plasticine could be a variant for ad hoc repairs.

 

[Infojunky]

I have a fair number of converted asteroid ships in MTU. Based on Nickel/Iron roids mostly.

Question of making one own custom roid is asked. I figure by the time you collect appropriate amount of mass, then make forms to contain that mass that will survive requisite heating to at least sinter the amalgamation into a solid useable form you will have spent the same amount of money as building a hull.

As repair of combat damage of said hulls, generally the ideas that have been floated in my games is tac-welding in replacement sheets on the inside then fill in the exterior divots with "Construction Foam™" mixed with Asteroid mining slag.

 

[Tom Kalbfus]

Lots of asteroids are piles of rubble in space. So do you attack a engine to a pile or rubble and call it a planetoid ship? With gravity control, you presumably can accelerate that pile of rubble however you like. Also another thought occurred to me. What if you wanted to use the ship's artificial gravity to give your planetoid ship spherical gravity? Lets say you start with an asteroid that is 2 kilometers in diameter, you put up grav plating to give it a 1-g field over its entire surface, then, 50 meters you have another layer of grav plating, this one produces a 100-G grave field, and the atmosphere surrounding the asteroid attenuates to a vacuum at a distance of 1 kilometer above the surface of the asteroid. And on the asteroid you have trees, gardens, ponds and the like, plus artificial light sources to help the plants grow underneath? Would that make an interesting starship

 

[Condottiere]

I forget.

How much gravity can gravitational plating induce, and how far does it extend?

We could probably cobble together larger bits of usable rubble, but how fast can it tolerate acceleration, and won't it be a variation of a dispersed structure, though the actual technical term would be a rock group.

 

[Tom Kalbfus]

I forget.

How much gravity can gravitational plating induce, and how far does it extend?

We could probably cobble together larger bits of usable rubble, but how fast can it tolerate acceleration, and won't it be a variation of a dispersed structure, though the actual technical term would be a rock group.

You need 100-gs to compress an atmosphere around a ship, so as to hold onto the atmosphere, that would normally extend outward by 100 kilometers around a planet like Earth, since we are talking only about a 2 km wide asteroid, we need much more gravity to hold onto an atmosphere, since gravity diminishes according to the inverse square law. So on the outside of the asteroid, you have a 1-G field and a breathable atmosphere on the surface, above 50 meters from that, you have a grav plate mesh, you go above that and you experience 100-gs, ascend to 1 km above that, you are doubling the radius and so the gravity diminishes to 25 gs, the atmosphere rapidly diminishes as you pull further away from the starship, you go another kilometer up and the gravity is reduced to 11.1 gs, climb another kilometer and its 6.25 gs, go up another kilometers and its 4 gs and so forth. You could make an asteroid's surface habitable with a strong outer gravity field.

 

[Condottiere]

But can you get technological level fifteen gravitation plates to induce a hundred gravities?

 

[DivineWrath]

Thanks for the feedback. It gives me ideas to play with.

Its not a big loss if I can't make asteroids for asteroid ships. Making hulls cheap isn't the only option to for making cheaper ships.

I'll probably allow asteroid ships to be repaired.

Use Astropaste. We promise it'll seal space rocks shut.

As for damage, an asteroid ship is effectively a ship with unused hull space that contributes to hull points and a little bit to armor. I think that anything that would damage a standard ship would damage an asteroid ship. Doesn't matter if the damage only makes a crater or something. Its either less mass protecting that location or structural integrity has been compromised.

 

[Condottiere]

First, we have to establish the extent of the damage to the planetoid; if might be cheaper and easier to reinstall the engineering components and electronics in a virgin rock.

 

[alex_greene]

Interesting premise. Find a decent-sized asteroid, silicon-based perhaps, grind the entire rock to hundreds of tons of fine powder, and 3D print the thing into a gigantic symmetrical sling bullet of a hollowed out ship. Outfit the hollowed out interior, add life support, drives and so on, add crew and turn the thing loose on the universe.

To repair it, just find more of the same sort of rock, or otherwise your smooth grey egg-shaped asteroid's going to develop some interesting patchwork surface details over time.

 

[Infojunky]

Interesting premise. Find a decent-sized asteroid, silicon-based perhaps, grind the entire rock to hundreds of tons of fine powder, and 3D print the thing into a gigantic symmetrical sling bullet of a hollowed out ship.

By the time you used all that energy you could have built a hull out of ceramics. Remember printing isn't a low energy solution, and strength is dependant on the binding material which has a significant energy and materials cost.

 

[alex_greene]

Interesting premise. Find a decent-sized asteroid, silicon-based perhaps, grind the entire rock to hundreds of tons of fine powder, and 3D print the thing into a gigantic symmetrical sling bullet of a hollowed out ship.

By the time you used all that energy you could have built a hull out of ceramics. Remember printing isn't a low energy solution, and strength is dependant on the binding material which has a significant energy and materials cost.

Solar power and fusion. It's doable. And why use artificial ceramics when Nature provides its own?

 

[Condottiere]

I don't see power being an issue once you manufacture fusion reactors, or even hook up our variant of solar panelling.

But I don't see a planetoid hull being constructed using three dee printers, when you could use a jello mold and bake it.

 

[Infojunky]

It's doable. And why use artificial ceramics when Nature provides its own?

That's easy, engineered materials give a uniformed response to the applied processes.

Now disassembling asteroids for raw feed stack is an idea, but one would want to carefully monitor the gross composition of the aggregate.

My point is that there is zero difference between ceramics and metals for hull construction, in that one needs to manufacture the parts to build the ships.

Another point is printing isn't the panacea of manufacturing that it is currently conflated to be. Don't get me wrong it is a wonderful addition the the bag of tools of industrial design, but a slow and expensive mode for large scale manufacturing.

 

[Infojunky]

I don't see power being an issue once you manufacture fusion reactors, or even hook up our variant of solar panelling.

Simple answer, Economics. You still have to buy the means of producing power....